It does not tell you whether an AI wrote it. It measures padding, which belongs to the text and not to its author: is it worth reading in full?
To compare paragraphs by meaning a multilingual AI model of about 150 MB is needed. It downloads once from Hugging Face and stays saved in your browser. It is the same one used by the embeddings, similarity and RAG tools: if you have used any of them, nothing is downloaded. Your text never leaves your device.
Connects to huggingface.co · *.cdn.hf.co · cdn.jsdelivr.net — only to download the file: nothing of yours is sent.
Press “Measure” and here you will see how much can be cut, which paragraphs are needed and which repeat the same idea in other words.